12687989 has 2 divisors, whose sum is σ = 12687990. Its totient is φ = 12687988.

The previous prime is 12687977. The next prime is 12688033. The reversal of 12687989 is 98978621.

12687989 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 11785489 + 902500 = 3433^2 + 950^2 .

It is a cyclic number.

It is not a de Polignac number, because 12687989 - 2⁸ = 12687733 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (12687089) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6343994 + 6343995.

It is an arithmetic number, because the mean of its divisors is an integer number (6343995).

Almost surely, 2^12687989 is an apocalyptic number.

It is an amenable number.

12687989 is a deficient number, since it is larger than the sum of its proper divisors (1).

12687989 is an equidigital number, since it uses as much as digits as its factorization.

12687989 is an evil number, because the sum of its binary digits is even.

The product of its digits is 435456, while the sum is 50.

The square root of 12687989 is about 3562.0203536757. The cubic root of 12687989 is about 233.2370811622.

The spelling of 12687989 in words is "twelve million, six hundred eighty-seven thousand, nine hundred eighty-nine".